BACKGROUND: Traditionally, stent thrombosis (STH) has been regarded as a complication of percutaneous coronary interventions during the first 30 post-procedural days. However, delayed endothelialization associated with the implantation of drug-eluting stents (DES) may extend the risk of thrombosis beyond 30 days. Data are limited regarding the risks and the impact of this phenomenon outside clinical trials. OBJECTIVES: To evaluate the incidence, predictors and clinical outcomes of STH and premature discontinuation of thienopyridines after implantation of DES in real-world practice. METHODS: We prospectively collected data from consecutive unselected patients who underwent at least 1 DES implantation at our center from February 2006 until January 2007. The patients were followed by a phone interview or by collecting data from admission files over the course of 2 years after the implantation. Confirmed and suspected STH was defined as accepted in the medical literature. RESULTS: Three hundred fourteen patients were successfully treated with DES (436 lesions). At 20 ± 6.7 months' follow up (median 22 months), 14 patients (4.4%) had STH (incidence density 2.7 cases/100 patients-years). Five patients had early thrombosis (0-30 days), 5 patients had late STH (31-360 days from the procedure) and 4 patients had very late STH (> 360 days). Five of the 14 patients with STH died (case fatality rate, 36%). In multivariant logistic regression analysis, history of a non-cardiac thrombotic event was a risk factor for STH (p = 0.006, odds ratio [OR] 7.7, confidence interval [CI] 1.8-32.9). Clopidogrel therapy lasting less than 3 months was an independent predictor of late and very late STH (p = 0.001, OR 10.8, CI 2.7-42.9). Independent predictors of early discontinuation of thienopyridines (≤ 3 months) were Arab ethnic origin (p = 0.005, OR 19.2, CI 2.4-142), absence of cardiology follow up (p = 0.05, OR 4.7, CI 1-23.1) and absence of explanation about the clopidogrel importance at the time of hospital discharge (p = 0.001, OR 10.8, CI 2.7-42.9). CONCLUSIONS: The incidence of STH at 22- month follow up in real-world patients was substantially higher than the rate reported in previous clinical trials. Subsidizing the cost of thienopyridines, providing a clear explanation to the patient and encouraging cardiology follow up may prevent premature discontinuation of thienopyridines after implantation of DES and reduce the incidence of STH after DES implantation.
BACKGROUND: Traditionally, stent thrombosis (STH) has been regarded as a complication of percutaneous coronary interventions during the first 30 post-procedural days. However, delayed endothelialization associated with the implantation of drug-eluting stents (DES) may extend the risk of thrombosis beyond 30 days. Data are limited regarding the risks and the impact of this phenomenon outside clinical trials. OBJECTIVES: To evaluate the incidence, predictors and clinical outcomes of STH and premature discontinuation of thienopyridines after implantation of DES in real-world practice. METHODS: We prospectively collected data from consecutive unselected patients who underwent at least 1 DES implantation at our center from February 2006 until January 2007. The patients were followed by a phone interview or by collecting data from admission files over the course of 2 years after the implantation. Confirmed and suspected STH was defined as accepted in the medical literature. RESULTS: Three hundred fourteen patients were successfully treated with DES (436 lesions). At 20 ± 6.7 months' follow up (median 22 months), 14 patients (4.4%) had STH (incidence density 2.7 cases/100 patients-years). Five patients had early thrombosis (0-30 days), 5 patients had late STH (31-360 days from the procedure) and 4 patients had very late STH (> 360 days). Five of the 14 patients with STH died (case fatality rate, 36%). In multivariant logistic regression analysis, history of a non-cardiac thrombotic event was a risk factor for STH (p = 0.006, odds ratio [OR] 7.7, confidence interval [CI] 1.8-32.9). Clopidogrel therapy lasting less than 3 months was an independent predictor of late and very late STH (p = 0.001, OR 10.8, CI 2.7-42.9). Independent predictors of early discontinuation of thienopyridines (≤ 3 months) were Arab ethnic origin (p = 0.005, OR 19.2, CI 2.4-142), absence of cardiology follow up (p = 0.05, OR 4.7, CI 1-23.1) and absence of explanation about the clopidogrel importance at the time of hospital discharge (p = 0.001, OR 10.8, CI 2.7-42.9). CONCLUSIONS: The incidence of STH at 22- month follow up in real-world patients was substantially higher than the rate reported in previous clinical trials. Subsidizing the cost of thienopyridines, providing a clear explanation to the patient and encouraging cardiology follow up may prevent premature discontinuation of thienopyridines after implantation of DES and reduce the incidence of STH after DES implantation.